aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-omap2/serial.c
blob: 93d102535c852d66a2b772b85b4d77e980a2ebb2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
/*
 * arch/arm/mach-omap2/serial.c
 *
 * OMAP2 serial support.
 *
 * Copyright (C) 2005-2008 Nokia Corporation
 * Author: Paul Mundt <paul.mundt@nokia.com>
 *
 * Major rework for PM support by Kevin Hilman
 *
 * Based off of arch/arm/mach-omap/omap1/serial.c
 *
 * Copyright (C) 2009 Texas Instruments
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/console.h>
#include <linux/omap-dma.h>

#include <plat/omap-serial.h>

#include "common.h"
#include "omap_hwmod.h"
#include "omap_device.h"
#include "omap-pm.h"
#include "soc.h"
#include "prm2xxx_3xxx.h"
#include "pm.h"
#include "cm2xxx_3xxx.h"
#include "prm-regbits-34xx.h"
#include "control.h"
#include "mux.h"
#include "serial.h"

/*
 * NOTE: By default the serial auto_suspend timeout is disabled as it causes
 * lost characters over the serial ports. This means that the UART clocks will
 * stay on until power/autosuspend_delay is set for the uart from sysfs.
 * This also causes that any deeper omap sleep states are blocked.
 */
#define DEFAULT_AUTOSUSPEND_DELAY	-1

#define MAX_UART_HWMOD_NAME_LEN		16

struct omap_uart_state {
	int num;

	struct list_head node;
	struct omap_hwmod *oh;
	struct omap_device_pad default_omap_uart_pads[2];
};

static LIST_HEAD(uart_list);
static u8 num_uarts;
static u8 console_uart_id = -1;
static u8 no_console_suspend;
static u8 uart_debug;

#define DEFAULT_RXDMA_POLLRATE		1	/* RX DMA polling rate (us) */
#define DEFAULT_RXDMA_BUFSIZE		4096	/* RX DMA buffer size */
#define DEFAULT_RXDMA_TIMEOUT		(3 * HZ)/* RX DMA timeout (jiffies) */

static struct omap_uart_port_info omap_serial_default_info[] __initdata = {
	{
		.dma_enabled	= false,
		.dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
		.dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
		.dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
		.autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
	},
};

#ifdef CONFIG_PM
static void omap_uart_enable_wakeup(struct device *dev, bool enable)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct omap_device *od = to_omap_device(pdev);

	if (!od)
		return;

	if (enable)
		omap_hwmod_enable_wakeup(od->hwmods[0]);
	else
		omap_hwmod_disable_wakeup(od->hwmods[0]);
}

/*
 * Errata i291: [UART]:Cannot Acknowledge Idle Requests
 * in Smartidle Mode When Configured for DMA Operations.
 * WA: configure uart in force idle mode.
 */
static void omap_uart_set_noidle(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct omap_device *od = to_omap_device(pdev);

	omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_NO);
}

static void omap_uart_set_smartidle(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct omap_device *od = to_omap_device(pdev);
	u8 idlemode;

	if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
		idlemode = HWMOD_IDLEMODE_SMART_WKUP;
	else
		idlemode = HWMOD_IDLEMODE_SMART;

	omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
}

#else
static void omap_uart_enable_wakeup(struct device *dev, bool enable)
{}
static void omap_uart_set_noidle(struct device *dev) {}
static void omap_uart_set_smartidle(struct device *dev) {}
#endif /* CONFIG_PM */

#ifdef CONFIG_OMAP_MUX

#define OMAP_UART_DEFAULT_PAD_NAME_LEN	28
static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
		tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;

static void  __init
omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
				struct omap_uart_state *uart)
{
	uart->default_omap_uart_pads[0].name = rx_pad_name;
	uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
							OMAP_DEVICE_PAD_WAKEUP;
	uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
							OMAP_MUX_MODE0;
	uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
	uart->default_omap_uart_pads[1].name = tx_pad_name;
	uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
							OMAP_MUX_MODE0;
	bdata->pads = uart->default_omap_uart_pads;
	bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
}

static void  __init omap_serial_check_wakeup(struct omap_board_data *bdata,
						struct omap_uart_state *uart)
{
	struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
	struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
	char *rx_fmt, *tx_fmt;
	int uart_nr = bdata->id + 1;

	if (bdata->id != 2) {
		rx_fmt = "uart%d_rx.uart%d_rx";
		tx_fmt = "uart%d_tx.uart%d_tx";
	} else {
		rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
		tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
	}

	snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
			uart_nr, uart_nr);
	snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
			uart_nr, uart_nr);

	if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
			omap_mux_get_by_name
				(tx_pad_name, &tx_partition, &tx_mux) >= 0) {
		u16 tx_mode, rx_mode;

		tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
		rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);

		/*
		 * Check if uart is used in default tx/rx mode i.e. in mux mode0
		 * if yes then configure rx pin for wake up capability
		 */
		if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
			omap_serial_fill_uart_tx_rx_pads(bdata, uart);
	}
}
#else
static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
		struct omap_uart_state *uart)
{
}
#endif

static char *cmdline_find_option(char *str)
{
	extern char *saved_command_line;

	return strstr(saved_command_line, str);
}

static int __init omap_serial_early_init(void)
{
	do {
		char oh_name[MAX_UART_HWMOD_NAME_LEN];
		struct omap_hwmod *oh;
		struct omap_uart_state *uart;
		char uart_name[MAX_UART_HWMOD_NAME_LEN];

		snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
			 "uart%d", num_uarts + 1);
		oh = omap_hwmod_lookup(oh_name);
		if (!oh)
			break;

		uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
		if (WARN_ON(!uart))
			return -ENODEV;

		uart->oh = oh;
		uart->num = num_uarts++;
		list_add_tail(&uart->node, &uart_list);
		snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
				"%s%d", OMAP_SERIAL_NAME, uart->num);

		if (cmdline_find_option(uart_name)) {
			console_uart_id = uart->num;

			if (console_loglevel >= 10) {
				uart_debug = true;
				pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
					uart_name, uart->num);
			}

			if (cmdline_find_option("no_console_suspend"))
				no_console_suspend = true;

			/*
			 * omap-uart can be used for earlyprintk logs
			 * So if omap-uart is used as console then prevent
			 * uart reset and idle to get logs from omap-uart
			 * until uart console driver is available to take
			 * care for console messages.
			 * Idling or resetting omap-uart while printing logs
			 * early boot logs can stall the boot-up.
			 */
			oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
		}
	} while (1);

	return 0;
}
core_initcall(omap_serial_early_init);

/**
 * omap_serial_init_port() - initialize single serial port
 * @bdata: port specific board data pointer
 * @info: platform specific data pointer
 *
 * This function initialies serial driver for given port only.
 * Platforms can call this function instead of omap_serial_init()
 * if they don't plan to use all available UARTs as serial ports.
 *
 * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 * use only one of the two.
 */
void __init omap_serial_init_port(struct omap_board_data *bdata,
			struct omap_uart_port_info *info)
{
	struct omap_uart_state *uart;
	struct omap_hwmod *oh;
	struct platform_device *pdev;
	void *pdata = NULL;
	u32 pdata_size = 0;
	char *name;
	struct omap_uart_port_info omap_up;

	if (WARN_ON(!bdata))
		return;
	if (WARN_ON(bdata->id < 0))
		return;
	if (WARN_ON(bdata->id >= num_uarts))
		return;

	list_for_each_entry(uart, &uart_list, node)
		if (bdata->id == uart->num)
			break;
	if (!info)
		info = omap_serial_default_info;

	oh = uart->oh;
	name = DRIVER_NAME;

	omap_up.dma_enabled = info->dma_enabled;
	omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
	omap_up.flags = UPF_BOOT_AUTOCONF;
	omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
	omap_up.set_forceidle = omap_uart_set_smartidle;
	omap_up.set_noidle = omap_uart_set_noidle;
	omap_up.enable_wakeup = omap_uart_enable_wakeup;
	omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
	omap_up.dma_rx_timeout = info->dma_rx_timeout;
	omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
	omap_up.autosuspend_timeout = info->autosuspend_timeout;
	omap_up.DTR_gpio = info->DTR_gpio;
	omap_up.DTR_inverted = info->DTR_inverted;
	omap_up.DTR_present = info->DTR_present;

	pdata = &omap_up;
	pdata_size = sizeof(struct omap_uart_port_info);

	if (WARN_ON(!oh))
		return;

	pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
				 NULL, 0, false);
	if (IS_ERR(pdev)) {
		WARN(1, "Could not build omap_device for %s: %s.\n", name,
		     oh->name);
		return;
	}

	if ((console_uart_id == bdata->id) && no_console_suspend)
		omap_device_disable_idle_on_suspend(pdev);

	oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);

	if (console_uart_id == bdata->id) {
		omap_device_enable(pdev);
		pm_runtime_set_active(&pdev->dev);
	}

	oh->dev_attr = uart;

	if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
			&& !uart_debug)
		device_init_wakeup(&pdev->dev, true);
}

/**
 * omap_serial_board_init() - initialize all supported serial ports
 * @info: platform specific data pointer
 *
 * Initializes all available UARTs as serial ports. Platforms
 * can call this function when they want to have default behaviour
 * for serial ports (e.g initialize them all as serial ports).
 */
void __init omap_serial_board_init(struct omap_uart_port_info *info)
{
	struct omap_uart_state *uart;
	struct omap_board_data bdata;

	list_for_each_entry(uart, &uart_list, node) {
		bdata.id = uart->num;
		bdata.flags = 0;
		bdata.pads = NULL;
		bdata.pads_cnt = 0;

		omap_serial_check_wakeup(&bdata, uart);

		if (!info)
			omap_serial_init_port(&bdata, NULL);
		else
			omap_serial_init_port(&bdata, &info[uart->num]);
	}
}

/**
 * omap_serial_init() - initialize all supported serial ports
 *
 * Initializes all available UARTs.
 * Platforms can call this function when they want to have default behaviour
 * for serial ports (e.g initialize them all as serial ports).
 */
void __init omap_serial_init(void)
{
	omap_serial_board_init(NULL);
}